Abstract
An excessively drained top soil was compacted to a range of bulk densities (1.3-1.7 t m-3) and the performances of a lowland rice variety (ADNY 11) under two moisture regimes of (i) continuous flooding and (ii) between saturation and -0.01 MPa water potential were measured in the glasshouse. Bulk densities of 1.5 and 1.6 t m-3, respectively, were optimal for plant performance for unflooded and flooded loamy sand soil. The interaction between bulk density levels and water regimes on rice plant performance was significant. Lowland rice root growth and distribution were more restricted to the surface soil in unflooded than under flooded conditions. The compaction levels which significantly affected the soil hydrological properties interacted with soil moisture regimes to affect rice general performance. Rice plants performed better under continuous flooding than under unflooded conditions.
